Basically a full kit has all the wood and hardware necessary to build the plane.
A short kit has all the laser-cut or die-cut wood pieces that are hard to cut by hand but does not have the sticks, sheets and other wood that is not die-cut or laser-cut, and does not have any hardware.

Found this on a site . . .
(quote) The Short Kit is the next best thing to Scratch Building, but without the hassle of having to cut out, or fabricate the parts. The Short Kits contain Construction Plans and all the “pre-shaped” wood and complex plastic parts where applicable. In most cases, the plans are CAD drawn, and the wood parts are laser cut, insuring good parts fit, making the model much easier to build then when using hand cut parts. As a Short Kit, the stock, readily available wood and wire sizes are not provided. (end quote)

Here is a short kit . . . http://www.meister-scale.com/FW190A/shortkit190a.html